DE 20 2015 101 156 U1 discloses such a filter element for a dirt suction device with a filter frame, on which a filter medium is attached, wherein a continuous seal is arranged on the filter frame, the inner circumferential surface of the seal being arranged on an outer circumferential surface of the filter frame. The seal has a section that protrudes radially over the filter frame.
Such filter elements can, for example, be designed so as to be rectangular or also round and are used particularly for household suction devices for suctioning wet or dry dirt. As a rule, the dirt suction device is designed such that the filter element can be very easily replaced.
Other dirt suction devices have a so-called cleaning function. When the filter is clogged with dirt, the suction flow is reversed, and so the dirt particles adhering to the filter element are blown off the filter element and drop into the dirt container, which can then be emptied.
Other cleaning methods operate mechanically, wherein the filter is scraped or shaken. For this cleaning method, the filter element must essentially be designed so as to be stable, and particularly the filter material, for example a filter fleece, must be durable and long-lasting.
Replaceable paper filters or filter fleeces made of plastic are used as filter materials.
Since the filter material of a filter element with filter frame is more stable and durable than, for example, simple paper filters, the weight and the mass of the filter element is also relatively high, and so the filter element inserted in the dirt suction device is subject to greater mechanical stress and wear.
In particular, the filter element must be sealed with respect to the filter receptacle and the dirt suction device, and so no external air can pass the filter element unfiltered.
Particularly, the seal of the filter element is mechanically highly stressed during suction and cleaning operation.
In case of dirt suction devices for wet operation, it must also be ensured that the sealing of the filter element is also guaranteed during wet operation.